Energy efficiency analysis of the Watchful Sleep mode in next-generation passive optical networks

Energy efficiency has become a salient element in the design and operation of modern telecommunications networks. To support energy efficiency in passive optical network (PON) systems, the ITU-T has recently standardized a new power management technique, namely the Watchful Sleep mode, which unifies the two previously standardized techniques (i.e., Doze and Cyclic Sleep modes). The new mode can emulate each of the Doze and Cyclic modes, and it outperforms them in terms of energy efficiency and reduced network signaling. In this paper, we present the first analytical model for numerically measure the performance of the Watchful Sleep mode. Specifically, the new model estimates the ONU's energy efficiency under different network scenarios given a set of quality-of-service constraints. To validate our model, we perform comparisons with simulation results. These comparisons demonstrate that the proposed model can accurately capture the energy efficiency of PON systems.